General > General Technical Chat
SOT-227(ISOTOP) vs TO-264 heat dissipation
(1/5) > >>
Fauks:
I'm working on making an electronic load and have narrowed it down to using a linear MOSFET in a SOT-227 module or a TO-264 package.

I would assume the module has better heat dissipation with better connections for thick wires vs using PCB traces. But according to the two data sheets (IXTK200N10L2, IXTN200N10L2) the TO-265 is rated a bit higher and also a bit cheaper. 

SOT-227 module:
SOA = VDS:100V, ID:5A, TC:75°C , tp:5s, 500W

TO-264:
SOA = VDS:100V, ID:6.25A, TC:75°C, tp:5s, 625W

Anyone with experience with these two packages? I'm still leaning toward the SOT-227 but I thought I would ask first.

Thank you!
T3sl4co1l:
Definitely the SOT-227: it's isolated, so can be put down with grease alone, and the heatsink grounded.  They have a DBC (direct bonded copper) isolator in there; some manner of ceramic, probably AlN, with copper deposited directly onto its surface as the name suggests.  This is present by default in module packages, I believe; it's rarely present in transistors otherwise, though does show up fairly often among rectifiers and thyristors.

But why not five TO-247s instead?  Of SJ types of suitable SOA, or QFETs if you can still get some.  Which way is cheaper?  Do you need the low saturation voltage, could you ballast up some or much of the range with resistors (in series, switched in parallel, etc.)?  There are many ways to slice this.  Resistors have the additional effect of reducing short-circuit current available to the transistor, in case the control goes batty, or the transistor fails catastrophically.

Tim
coppercone2:
the module has so many advantages like being easy to replace without messing with a heavy board or whatever you figure out.

if you can use wire then use it

heatsink on board sucks anyway if you can get away from it get away from it. You get so much flexibility in mechanical design from having a wire

They like TO-264 in premium power electronic solutions (i.e. non budget welders).
tooki:

--- Quote from: Fauks on March 22, 2024, 05:35:14 pm ---I'm working on making an electronic load and have narrowed it down to using a linear MOSFET in a SOT-227 module or a TO-264 package.

I would assume the module has better heat dissipation with better connections for thick wires vs using PCB traces. But according to the two data sheets (IXTK200N10L2, IXTN200N10L2) the TO-265 is rated a bit higher and also a bit cheaper. 

--- End quote ---
FYI, you posted two different screenshots of the same datasheet, not of the two different ones.
wraper:

--- Quote from: coppercone2 on March 22, 2024, 06:35:55 pm ---heatsink on board sucks anyway if you can get away from it get away from it. You get so much flexibility in mechanical design from having a wire

--- End quote ---
People put heatsinks along the edge of the board all the time just fine. In fact it's way less job mounting like that if done properly rather than running 3 or 4 wires with lugs crimped. IMHO using SOT-227 makes sense in something like industrial equipment cabinet with modules wired together and it being used like a module. It makes very little sense inside a device that is not supposed to be serviced in the field.
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod